Quasi-Z-source inverter model prediction control method without weight coefficient

Abstract

The invention discloses a quasi-Z-source inverter model prediction control method without a weight coefficient. The method comprises steps of acquiring voltage and current signals of a quasi-Z-sourceinverter; establishing a mathematical model of the quasi-Z-source inverter; establishing a prediction model of each control object of the quasi-Z-source inverter, and adding a delay compensation strategy; calculating a reference value of each control object; and determining the priority of a quasi-Z-source inverter control object according to a cascade model predictive control method in combination with the specificity of inductive current. Compared with a traditional finite set model predictive control method, by using the cascade model predictive control method, the prediction control methodhas the advantages that the weight coefficient is effectively eliminated, the control method is simpler, and the calculated amount of a digital processor is reduced.

Description

technical field [0001] The invention discloses a model predictive control method of a quasi-Z source inverter without a weight coefficient, and belongs to the control field of the quasi-Z source inverter. Background technique [0002] As a new type of inverter topology, quasi-Z-source inverter (qZSI) can overcome the shortcomings of traditional inverters and has its own boost function, which is very suitable for new energy power generation occasions such as photovoltaics. At present, the research on the control method of the Z-source inverter is mainly divided into two categories, one is the traditional modulation method, mainly sinusoidal pulse width modulation (sinusoidal pulse width modulation, SPWM) method and space vector modulation (space vector PWM, SVPWM) method; the other is a nonlinear control method based on model predictive control. Compared with the traditional modulation method, the model predictive control method has the characteristics of no modulation, simp...

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Problems solved by technology

Although the above method can achieve good control of the aligned Z-source inverter, there are three weight coefficients in the cost function that need to be adjusted at the same time, and there is currently no suitable design rule to guide the design of the weight coefficients, so when a cost function has multiple When the weight coefficient is used, the adjustment of the weight coefficient will become extremely cumbersome. If the weight coefficient is not designed properly, it will cause the quasi-Z source inverter to fail to work normally. In addition, this method also has the disadvantage of a large amount of calculation, which gives Digital processors bring some computational pressure

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